Providing adequate analgesia to patients prior to performing procedures is not only beneficial to patient, but also aids the clinician. Importantly, the patient's experience of the entire process will often determine how happy they feel about the eventual outcome. Often the most painful part of the procedure in community and emergency department settings will be the infiltration of the local anaesthetic.

With infiltrating local anaesthetic there are a number of tips, tricks and steps that you can take to simplify the process and minimise the pain. I have sourced this advice from my fellow clinicians, the literature and across the web. If you have any tips please feel free to share them in the comments section below. This is an adjunct post to the Basic Guide to Suturing Series.

So here is the quick users guide to reducing the pain of and improving your local anaesthetic administration.

Dose Correctly

Getting the right dose either using the traditional calculations or this handy little dosing nomogram - http://www.aliem.com/pv-card-local-anesthetic-toxicity-calculations/
And from the literature http://onlinelibrary.wiley.com/doi/10.1111/anae.12679/full

IBW Calculator - http://www.mdcalc.com/ideal-body-weight/#about-calculator
 

	Onset (min)	Duration (min)	Max dose (mg/kg)	Max mg (70kg person)
Lignocaine (1% or 2%) (Xylocaine)	2	15-60	3mg/kg	220mg (11mL 2%) (22mL 1%)
Lignocaine with adrenaline (1% or 2%)	2	120-360	7mg/kg	500mg (25mL 2%) (50mL 1%)
Bupivicaine (0.25%) (Marcain)	5	120-240	2.5mg/kg	175mg(50mL)
Bupivicaine with adrenaline	5	180-420	3mg/kg	225mg
Prilocaine (0.5% or 1%) (Citanest)	2	30-90	7mg/kg	500mg<70kg 1="" ml="" td="">
Ropivocaine (0.25%) (Naropin)	5	120-360	3mg/kg	225mg

Solution preparation for minimal pain

Appropriate dosing
Buffer with sodium bicarbonate(e.g. 1mL of 8.4% sodium bicarbonate to 9 mL of 1% lignocaine.)
Warm the LA

Equipment

Smallest needle
Longer needle: requiring fewer injection points to cover the same area
Consider using a diabetic needle for first infiltration
Use fresh needles (i.e. sharper needles)
Appropriate syringe size (less pressure, and less likely to overdose)

Patient preparation

Look away
Distraction (e.g. smartphones, music, tv)
Gentle pinching or vibration adjacent to the site of injection

Paediatric Population

Use 1% for paeds patients.
Play specialist
Topical Analgesia
- ALA (Laceraine): a combination of 0.5% amethocaine, 4% lignocaine and 0.1% adrenaline
- EMLA is non-sterile and not approved for application to broken skin
Consider other options; e.g. gas, procedural sedation etc.

Further reading;
RCEM: Paediatric Wound Management
LITFL: Kids, Cuts and Clinical Care

Procedural

Topical Anaesthetic
Inject into Subcutaneous Fat if There Is an Open Wound
Infiltrate through wound edges, rather than unbroken skin (clean wound)
Stabilise the Syringe Holding Hand to Minimise Needle Movement
Inject Very Slowly
Keep the Local Anaesthetic Wheal 10 mm ahead of the Needle Tip
Decrease number of insertions
Use smallest volume necessary

Get feedback from your patients

Getting feedback from your patients can help learn what works and what does not when administering local anaesthetic, to give the patient the most ideal experience.

References/Further Reading

http://www.ncbi.nlm.nih.gov/pubmed/17499653 
http://www.mdedge.com/cutis/article/100528/practice-management/minimize-pinch-and-burn-tips-and-tricks-reduce-injection

Sexual Health goes beyond just the mechanical motions of sexual intercourse, and encompasses much more, including but not limited too; relationships, gender identity, contraception and pregnancy, infectious diseases and sexual assault.

This post provides just a brief introduction to the world of Sexual Health, particularly looking at Sexually Transmitted Infections (STIs)/Diseases and Blood Borne Viruses (BBVs).

Key Resources

Rather than my traditional way of keeping the goodies to till the end, I have provided some key open access resources specific to STIs which I think should not be overlooked.

- STI Tool

- STI Atlas

- Australian STI Management Guidelines

Approach

The NSW STI Programs unit has put a nice simple approach together for clinicians to follow in STI assessment and management.

1. 1. Start the conversation about Sexual Health.
2. - Consider approach language for that demographic
3. - Ensure a safe environment
4. - History and assess risk factors
5. - Examination as appropriate
6. 2. What and how to test your patients.
7. - Testing based off earlier assessment and population groups
8. - Consider most appropriate method of testing (e.g. swab, urine, blood test)
9. - Opportunistic testing (e.g. doing a high vaginal swab, whilst doing a Pap Smear)
10. 3. Contact Tracing
11. - Prevent re-infection for your patient and the onward transmission of the disease.
12. - Understand the timeframes for specific STIs
13. - Using the appropriate resources to contact trace and inform third parties

NSW STI Programs unit's four page quick cheat sheet is available here.

Rules of Sexual Health

1. 1. Assume nothing. 
2. 2. All STIs can produce disease without causing symptoms.
3. 3. More than one STI or BBV can be present
4. 4. Do not presume that the presenting genital problem is the only problem.
5. 5. Respect difference.

Sexual Health History

The importance of communication and language can and should never be down played in consulting, however it is particular important in Sexual Health. The correct use of language can make; people feel comfortable opening up to you on topics that might be very personal to them, feel validated and that you understand them as a person and their associated identity, help them risk mitigate and manage their own condition moving forward. Clarifying the language the patient uses regarding genitals and what sexual intercourse means to them is also important step.

For example in Men who have Sex with Men (MSM) in regards to anal sex, you may want to find out who is penetrating and who is receiving. These terms may for them personally, and it will sometimes require more simple or vulgar language -> “Did you fu*k him in the butt or did he fu*k you?”

Below are some areas to get you started and think about. I am however, not expert in this area so I've included a link to the Australian STI Guidelines take on Sexual History Taking.

Regular Partners

Other Partners

Nature of Sexual Contact

Condom Use

Past history of STI

Overseas Contact

Sexual function difficulties

What age did the patient first experience sexual contact

Of course for all females; are you or is there a possibility you could be pregnant.

Aside from taking a more focussed Sexual Health History, you still need to cover your standard Past Medical History, Allergies, Medications, Social History and so on.

I have always like the HEEADSSS psychosocial interview and despite being designed for adolescents I think it can be often used and adapted if required for any age of life. In the context of sexual health, I think that it can a useful tool to assess factors that may positively or negatively influence their sexual health. In addition, guide appropriate testing and management strategies that are more applicable to that individual.

H – Home 

E – Education & Employment 

E – Eating & Exercise 

A – Activities & Peer Relationships 

D – Drug Use/Cigarettes/Alcohol 

S – Sexuality 

S – Suicide and Depression (including mood &possible psychiatric symptoms) 

S – Safety (also Spirituality)

If you are really floundering in what to ask for in a Sexual Health History or just like something short and snappy to remember than think of The 5 P's for Sexual History.

P artners 

P revention of Pregnancy 

P rotection from STDs 

P ractices 

P ast History of STDs

The CDC has developed this little handout that goes in to the 5 P's a little more.

Common Sexual Health Diseases

Prevalence of the various STIs is dependant upon the region in which you live and work. However, there are a number that are fairly common globally which I will cover below.

Like most things in life, be aware of what is going around in your local patch, and the strategies that are used locally.

The Quick Guide to STI Management from Western Australian Department of Health covers nearly all the common sexual health diseases. Remember to check your local guidelines as well, however this is short and succinct document if all else fails.

Asymptomatic Testing

Tests for all sexually active people.

Chlamydia (males):  FPU - NAAT

Chlamydia (females): Endocervical swab – NAAT , Self-collected vaginal swab – NAAT , FPU – NAAT, Ano-rectal swab 

Consider the following tests for individuals who are not from a high risk population group. To determine risk, take a sexual history.

Hepatitis B: Blood – HBsAg, Anti-HBs, Anti-HBc 

HIV: Blood – HIV Ag/Ab 

Syphilis: Blood – Syphilis serology 

Additional test to consider in asymptomatic individuals.

Gonorrhoea: NAAT and/or Culture

Also give the STI Tool a go to help determine what test you might need.

Population Groups

For more details regarding Sexual Health assessment in particular population groups
click below;

Aboriginal and Torres Strait Islander people 

Adult Sexual Assault 

MSM - Men who have sex with men 

People in correctional facilities 

PLWHIV - People Living with HIV 

Pregnant Women 

PWID - People who inject drugs 

Refugees (and newly arrived migrants from similar settings) 

Regional/Remote 

Sex workers 

Transgender 

WSW - Women who have sex with women 

Young people

A Career in Sexual Health

Interested in a Career in Sexual Health Medicine in Australia? See the Royal Australasian College of Physicians for more details about how to expand your skills in this area.
This flyer provides a brief overview of the program.

References and Resources

1. 1. The 5 P's for Sexual Behaviour History Taking: https://aidsetc.org/resource/5-ps-sexual-behavior-history-taking
2. 2. STI Tool: http://www.mshc.org.au/Portals/0/Documents/HealthProfessional/STITool/stiTool1.7.pdf
3. 3. STI Atlas: http://stiatlas.org/SearchAtlas.aspx
4. 4. STI Guidelines: http://www.sti.guidelines.org.au/
5. 5. ReachOut.com: https://au.reachout.com/relationships
6. 6. CDC - A Guide to Taking a Sexual History: https://www.cdc.gov/std/treatment/sexualhistory.pdf
7. 7. NSW STI/HIV Testing Tool: https://stipu.nsw.gov.au/wp-content/uploads/STI-HIV-Testing-Tool-online.pdf 
8. 8. Western Australian Department of Health - SilverBook Guidelines for managing sexually transmitted infections and blood-borne viruses: http://ww2.health.wa.gov.au/Silver-book

This post is part of the Basic Guide to Suturing series. Here we take a look at using local anaesthetic, to help us manage a simple wound/laceration. 

Firstly a recap of the wound management process.

1. 1. Assess
2. 2. Gather required equipment
3. 3. Prep & Drape
4. 4. Anaesthetise
5. 5. Clean/Irrigate
6. 6. Suture (see Overview of Suturing Techniques for more details)
7. 7. Bandaging/Dressing and ongoing wound-care

Remember if cleaning the wound is painful or difficulty to examine, anaesthetising earlier may be beneficial and kinder to your patient.

Indications

◘ For pain control and analgesia during a procedure or assessment

Contraindications

◘ Known allergic reaction or anaphylaxis

◘ Large or multiple lacerations requiring significant doses

◘ Local tissue infection (relative)
◘ Patient refusal

Precautions

◘ Intravascular injection of local anaesthetic (injection should follow Aspiration to ensure extravascular administration)

◘ Use of adrenaline (see below for areas and particular patients where caution should be used)

◘ Prior adverse reaction (including vasovagal reaction)

◘ Pre-existing neurological and cardiac disorders

◘ Hepatic or renal impairment 

A bit about Local Anaesthetics

“A local anaesthetic can be defined as a drug which reversibly prevents transmission of the nerve impulse in the region to which it is applied, without affecting consciousness.” FRCA

It is important as a Medical Student or Junior Doctor to have a basic understanding of the side-effects, doses and key properties of common local anaesthetics. In general, local anaesthetics work by stabilising the neuronal membrane and preventing the transmission of nerve impulses.

An overview of Lignocaine is provided here. For other agents, see the comparison table below.
For more details see Local Anaesthetics by the Royal Adelaide ICU, useful resource for those studying for the various critical care primary examinations.

Lignocaine/Lidocaine/Xylocaine

Lignocaine is one of the most commonly used local anaesthetic agents. It is suitable for surface, infiltration, nerve block, caudal, epidural, and spinal anaesthesia.


MOA
Binds selectively to refractory Na+ channels -> preferentially when cells are depolarised

Dosing

◘ Maximum dose of lignocaine without adrenaline is ~3 mg/kg.

◘ Maximum dose of lignocaine with adrenaline is ~7 mg/kg. 

Adverse effects

◘ lightheadedness

◘ hypotension

◘ cardiovascular collapse
◘   heart block
◘ confusions
◘ seizures

Adrenaline/Epinephrine

Adrenaline is a common additive in your local anaesthetic. Acting as a vasoconstrictor, it helps prolong the action of your local anaesthetic, decrease systemic absorption and risk of toxicity, and reduce traumatic blood loss. Consequently, it also allows you to deliver a higher dose of your local anaesthetic.

Contraindications

◘ Conditions where tachycardia is detrimental (thyrotoxicosis, CCF, IHD)

◘ Periorbital infiltration in patients with narrow angle glaucoma

◘ Digital anaesthesia in patients with peripheral artery disease 

Precautions

◘ Patients with catecholamine sensitivity

◘ Patients taking monoamine oxidase inhibitors, beta blockers, anti-arrhythmics, phenothiazines, or tricyclic antidepressants

◘ Pregnant patients
 

Equipment

◘ Local Anaesthetic Agent

◘ Syringe (e.g. 5ml, 10ml)

◘ Needles (large sharp or blunt drawing up needle; 25-30G needle for infiltration)

◘ Personal protective equipment

◘ Skin cleansing agent (e.g. alcohol swabs/wipes, chlorhexidine or povidone-iodine solution)

◘ Sterile Gauze

Dosing

Be aware of the parameters of the Local Anaesthetic you are using and it's safety profile.

See the table below for common local anaesthetic agents. More details on how to accurately dose local anaesthetics in Optimising Local Anaesthetic Administration.

Procedure (local infiltration)

1. 1. Discuss with and gain patient consent for the procedure.
2. 2. Consider use of topical analgesics, as they will take some time to work.
3. 3. Gather required equipment and don PPE.
4. 4. Draw up your local anaesthetic by either sharp or blunt needle, or directly via syringe from the ampule.
5. 5. Prepare skin with cleansing agent (chlorhexidine or povidone-iodine) if infiltrating through intact skin. Allow skin to air-dry or dry with your sterile gauze.
6. 6. Remove any gross contamination inside the wound with normal saline.
7. 7. Then insert the needle directly though the wound edge (rather than intact skin where possible) into the subcutaneous layer.
8. 8. Aspirate to rule out intravascular placement.
9. 9. Advance needle forward and slowly inject small volumes of LA. Alternatively advance needle the full distance and inject slowly on withdrawal.
10. 10. Remove needle.
11. 11. Repeat until the area is fully anaesthetised or maximum dose is reached. Re-insert the needle if required through previously anaesthetised areas.
12. 12. Wait for the anaesthetic to take effect, and then test for adequate coverage. Use either your injection needle or other sharp object (e.g. suture needle) to test anaesthetic coverage.
13. 13. You are now free to further examine, clean/irrigate the wound or begin your primary procedure (e.g. suturing).

Post-Procedure Care 

Patients should be advised of likely timeframes for recovery of full sensation after Local Anaesthetic administration. Consequently, it is also important to assess neurovascular status prior to injecting local anaesthetic.

They should also lookout for/represent if;

◘ infection or neurovascular compromise

◘ systemic toxicity 

◘ allergic reaction

Optimising local administration

Stay tuned for my upcoming post on Optimising Local Anaesthetic Administration for handy tip/tricks.

Local Anaesthetic Table

	Onset (min)	Duration (min)	Max dose (mg/kg)	Max mg (70kg person)
Lignocaine (1% or 2%) (Xylocaine)	2	15-60	3mg/kg	220mg (11mL 2%) (22mL 1%)
Lignocaine with adrenaline (1% or 2%)	2	120-360	7mg/kg	500mg (25mL 2%) (50mL 1%)
Bupivicaine (0.25%) (Marcain)	5	120-240	2.5mg/kg	175mg(50mL)
Bupivicaine with adrenaline	5	180-420	3mg/kg	225mg
Prilocaine (0.5% or 1%) (Citanest)	2	30-90	7mg/kg	500mg<70kg 1="" ml="" td="">
Ropivocaine (0.25%) (Naropin)	5	120-360	3mg/kg	225mg

Alternatives

Nitrous oxide (Entonox®), topical analgesia, sedation, general anaesthesia

Local Anaesthetic Toxicity

LITFL: Guide to Local Anaesthetic Toxicity
LITFL: CCC Local Anaesthetic Toxicity

References:

LITFL: Lignocaine
Essentials of Local Anesthetic Pharmacology (2006)

STI Atlas is a repository of images covering a vast array of sexually transmitted infections. It has been put together by the Melbourne Sexual Health Centre for teaching purposes.

STIAtlas.org

The Australian STI Management Guidelines are the Penultimate resource for Primary Care Doctors (whether in the community or emergency departments). The guidelines are available at; http://www.sti.guidelines.org.au/

Please refer to Populations & Situations for asymptomatic screening recommendations, Syndromes for guidance about managing specific clinical scenarios and to STIs for specific management of a diagnosed infection..

STI

• Chancroid
• Chlamydia
• Donovanosis
• Ectoparasites
• Genital warts
• Gonorrhoea
• Hepatitis A
• Hepatitis B
• Herpes
• HIV
• LGV - Lymphogranuloma venereum
• Mycoplasma genitalium
• Syphilis
• Trichomoniasis

Infections associated with sex

• Bacterial Vaginosis
• Candidiasis
• Hepatitis C

Syndrome

• Ano-genital Lumps
• Ano-genital Ulcers
• Ano-rectal Syndromes
• Cervicitis
• Epididymo-orchitis
• PID - Pelvic inflammatory disease
• Skin rash - generalised
• Skin rash - genital
• Urethritis - male
• Vaginal discharge

Populations & situations

• Aboriginal and Torres Strait Islander People
• Adult Sexual Assault
• MSM - Men who have sex with men
• People in correctional facilities
• PLWHIV - People living with HIV
• Pregnant women
• PWID - People who inject drugs
• Refugees (and newly arrived migrants from similar settings)
• Regional & remote
• Sex workers
• Transgender
• WSW - Women who have sex with women
• Young people

This Tool has been prepared by the Melbourne Sexual Health Centre as an aid for GPs, providing simplified guidelines for STI screening and for dealing with common symptomatic presentations.

Click here to view version 1.7

Go to http://www.mshc.org.au/ for latest version

It covers;
Males Problems

1. - screening
2. - urethral symptoms
3. - lumps or swellings
4. - ulcers or sores
5. - skin rash and/or itch

Female Problems

1. - screening
2. - vaginal discharge, no vulvar symptoms
3. - pelvic pain
4. - vulvar symptoms +/- discharge
5. - lumps or swellings
6. - ulcers or sores
7. - skin rash and/or itch

This post is part of the Basic Guide to Suturing series. It provides an overview of the steps you need to take when assessing and then preparing for closure of a wound. 

As a general guide you would normally;

1.   1.  Assess
2.   2.  Gather required equipment
3.   3.  Prep & Drape
4.   4.  Anaesthetise
5.   5.  Clean/Irrigate
6.   6.  Suture (see Overview of Suturing Techniques for more details)
7.   7.  Bandaging/Dressing and ongoing wound-care

Steps 3, 4 and 5 can be rearranged, depending on your operating environment, equipment, wound and personnel. In the Emergency Department in particular, the order is flexible, and steps may have to be repeated. For example, you might clean the wound first to remove of the majority of the debris so that you can use your local anaesthesia in a semi-sterile environment. Once the local is working, you could give the wound a more thorough clean again.   

Assessment of Wound

Your assessment of the wound is ultimately going to determine how choose to manage it. Some important characteristics to discuss and examine are;

◘  Mechanism of injury?

◘  How old is the injury?

◘  Where is the injury, how big and how deep?
◘  Examine for foreign bodies and/or contamination
◘  Assess neurovascular status and any search for any deep tissue issue injuries (e.g. tendons)
◘  Need for tetanus prophylaxis
◘  Identify risk factors that may affect wound healing

Based off history and examination consider requirement for any imaging. 

Tip: Achieving some degree of haemostasis is an important step in adequately assessing the wound. In emergency departments this can often be achieved by; applying direct pressure with a gauze pad for 10-15 minutes, or 1% lignocaine with adrenaline (other methods exist).

Indications (for suturing)

In general sutures can be used for wounds that have occurred within 18hrs of the initial injury. This in order to achieve;

◘  Haemostasis

◘  Bring tissues edges together, close defects

◘  Prevent further infection
◘  Securing drains or lines

Contraindications (for suturing)

Concern about wound infection is the primary reason not to close a wound primarily. Several relative contraindications exist for suturing and other methods of wound closure should be considered.

◘  Animal bites

◘  Foreign bodies/debris in wound

◘  Requires excessive tension
◘  Current infection
◘  Patients presenting with wounds >24hrs after initial injury

Equipment

Once you have decided to close the wound you need to get the appropriate equipment.

1.   1.    Sterile gloves
2.   2.    Sterile Syringe 5-10ml
3.   3.    Suture pack
4.   4.    Sutures
5.   5.    21-30G Needles (25G is commonly used.)
6.   6.    Local Anaesthetic (e.g. Lignocaine)
7.   7.    Antiseptic solution
8.   8.    Sharps bin
9.   9.    Formal Drapes (as required)
10. 10.    Dressings
11. 11.    Consider other Personal Protective Equipment

Preparation

If you have not done so already inform the patient about what you are about to do, and make sure they are happy to proceed. Written consent is often not required when repairing simple lacerations and verbal consent will often suffice. If unsure, talk to your senior clinician.

1.   1.   Get all your equipment (as listed above) and a trolley (where able)
2.   2.   Open your equipment using sterile technique and create a sterile field.
3.   3.   Ensure that both you and the patient are positioned in a comfortable manner.
4.   4.   Good lighting.
5.   5.   Wash your hands
6.   6.   Place on a pair of a sterile gloves (regular gloves may also be appropriate).
7.   7.   Clean the wound/s.
8.   8.   If painful consider anaesthetising at this point before any further cleaning.
9.   9.   Irrigate with chosen solution
10. 10.   Normal Saline, Dilute Iodine or even tap water (see below)
11. 11.   Use your drapes (creating a hole if necessary) to cover the wound 
12. 12.   If you have not done so already, Get ready to anaesthetise!

Tip: It is may seem obvious, but it is less painful to anaesthetise through the wound, rather than break through fresh skin with a needle to achieve numbness.

References

Stitch Up by Martin Clifton

Suturing, one of the fundamental skills of a medical practitioner has been around since the time of the Ancient Egyptians. Originally used by the Egyptians for burial preparations, the art of suturing has gone through several renditions throughout the course of history. Yet it still remains one of the chief ways of allowing us to manipulate the body to help others and achieve wound closure.

This series of posts aim to provide a simple guide to the art of suturing. Covering common suture techniques, knot tying, surgical instrumentation, suture material and suture selection. Importantly, it will also cover some other aspects of medicine which are vital to understand to achieve optimal suture results:

◘ Anatomy

◘ Principles of wound care

◘ Anaesthesia

I’ve provided a collection of resources so that people can select those items which are most beneficial to their learning style. Look out for resources as they are added under the sections below.

The presentation below is an overview of the material covered throughout this series.

Suturing 101 - Basic Surgical Skills for Medical Students and Junior Doctor

Wound Assessment

History  and examination are the building blocks of wound assessment, and ultimate influence what you end up doing. Some important steps are highlighted below.

◘ Mechanism of injury

◘ How old is the injury

◘ Where is the injury, how big and how deep

◘ Examine for foreign bodies and/or contamination

◘ Assess neurovascular status and any search for any deep tissue issue injuries (e.g. tendons)

◘ Need for tetanus prophylaxis

◘ Identify risk factors that may effect wound healing

This is by no means a complete list of questions you should ask when a patient presents with an injury. The normal components of a standard medical history (e.g. allergies) are also an important component of your treatment strategy. 

Anaesthesia & Preparation

◘ Before you close the wound

◘ Anaesthetics for Wound Management

◘ Optimising Local Anaesthetic Administration
◘ Digital Ring Block
◘ Biers Block

Suture Techniques

◘ An overview of Suturing Techniques

◘ Simple interrupted suturing

◘ Vertical Mattress
◘ Continuous Subcuticular
◘ Horizontal Mattress

Knot Tying

◘ Grog's Surgical Knots

◘ Basic Square Knot (Boston University)

◘ Two Hand Tie (Boston University)
◘ One Hand Tie (Boston University)
◘ Instrument Tie (Boston University)

Other Management Options

◘ Staples

◘ Glue

◘ Steristrips

Take your Basic Surgical Skills a step further

There are lots of different resources out there to help further refine your skills.
Closing the Gap
Different DIY suture models

References & Resources

1. 1. Basic Laceration Repair, NEJM (2006)
2. 2. Stitch Up by Martin Clifton

A systematic approach to Chest X-Ray (CXR) interpretation is essential to avoid missing significant pathological changes. With time and practice, interpreting CXRs will become easier, but first you have to find an approach that works for you.

The Basics

Before we begin with our approach to CXR interpretation, there are some principles we need to understand. A chest radiograph uses ionising radiation (usually 0.06 mSv) to paint a picture of your internal chest anatomy. The dose of radiation from an individual X-Ray is typically of little concern. However if you're worried check out XKCD's Guide to Radiation.

It is important to note that not all chest structures will be seen on CXR, and some will only show up if an abnormality is present (e.g. pleura).

Adapted from Wikipedia

4 Main Radio-densities

When looking at a CXR it's important to get a grasp on anatomical & foreign structures will be presented. There are 4 main Radio-densities to be aware of;

◘  Gas = Black

◘  Fat = Dark grey

◘  Water = Light grey

◘  Bone/metal = White

Rule 1: The denser the tissue, the whiter it will appear on x-ray.

Views

The next thing to consider is what angle are you viewing the chest from. The most common view is the Posterior-Anterior, otherwise known as a PA film. Other views are;

◘  Anterior-posterior (AP)

- Exaggerates heart size. 

- For less mobile or emergency patients.

◘  Lateral CXR

◘  Decubitus

◘  Oblique

◘  Supine or standing?

 

Interpreting for Beginners

We will start with the most simple of interpretation methods that apply nearly to all radiological images.

Rule 2: Always check Patient Details & Film Type.

◘  Who: correct patient

◘  When: correct day

◘  Why: what is the indication for the test / what are we looking for?

◘  What: what is the image of?

These basic questions will set you in good stead before commencing on the intricacies of interpreting. Next consider, what systems are present in the image, and then identify and examine them.

Mnemonics can be a good way of making sure that you don't miss anything when your first starting out. I've included a number of examples below. At the end of the day, your approach to CXRs is basically what works for you.

Simple Interpretation
1. Check patient details & technical adequacy.    

2. ABC Method – Airways, breathing, circulation.

ABC Method

Airways

◘  Trachea

◘  Hilar

Breathing & Bones

◘  Lung fields, pleura. Costophrenic Angles.

◘  Bones – destruction, #s

Circulation & Soft tissues.

◘  Mediastinum – width.

Another option is the;

DCBAA Method
D ocuments
C hest

◘  Compare lungs

◘  Airway (right place, deviation)

◘  Mediastinum

◘  Diaphragm

◘  Pleura

B ones

◘  Look at all the bones.

◘  Pattern recognition.

A bdomen

◘  Frees gas - erect Chest X-Ray under diaphragm. 

A nd Areas

◘  Additional areas that you wouldn't normally look at.

Common Mistakes
This list of common mistakes comes courtesy of Duncan;

◘  Did I stop looking after I found one abnormal finding? Do I need to complete my system?

◘  What are the commonly missed things in this situation/imaging modality?

◘  Am I tired / bored / distracted?

◘  How do the clinical findings and the radiographic findings correlate?

◘  Have I examined the patient properly (ED juniors, a shoulder x-ray is not a substitute for an examination)

Beyond the Basics - ABCDEFGHI Method

A  Airway (midline, patent)

B  Bones (eg, fractures, lytic lesions)

C  Cardiac silhouette size

D  Diaphragm (eg, flat or elevated hemidiaphragm)

E  Edges (borders) of the heart (to rule out lingular and left middle lobe pneumonia or infiltrates)

F  Fields (lung fields well inflated; no effusions, infiltrates, or nodules noted)

G  Gastric bubble (present, obscured, absent)

H  Hilum (nodes, masses)

I   Instrumentation (eg, lines, tubes)

The DRSABCDE Method

Developed by Matthew Lumchee, the DRSABCDE method brings back the familiarity of the Basic Life Support algorithm whilst throwing in some additional features to CXR Interpretation. For more details on this method checkout Lifeinthefastlane.com.

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Further Resources

1. 1. Chest X-Ray Atlas - http://www.meddean.luc.edu/lumen/meded/medicine/pulmonar/cxr/atlas/cxratlas_f.htm
2. 2. Medline: Chest X-Ray (info for patients) - http://www.nlm.nih.gov/medlineplus/ency/article/003804.htm
3. 3. Radiology Masterclass - http://radiologymasterclass.co.uk/index.html
4. 4. Radiopedia.org (an atlas)
5. 5. The Radiology Assistant

Not quite sure how to interpret an ECG? 

Then have a look at A Quick Guide to ECG.

References

Crausman RS. The ABCs of chest X-ray film interpretation. Chest. 1998 Jan;113(1):256–7.
Chest X-Ray by Tor Ercleve